Carburetor structure



May 30,1939. A. H BLATTNER mL 2,160,411

CARBURETOR S TRUC TUBE ZN VEN T025 v qgasf H. /aner. Fred H. Kommer.

May 30, .1939. A. H. BLATYNERL- f AL y2,160,411

CARBURETR STRUG TURE Filed July 2,'1936 2 sheets-sheet 2 Patented May so, 1939 PATENT OFFICE CARBURETOR STRUCTURE August H. Blattner, Pine Lawn, and Fred A.

Kommer, St. Louis, Mo., assignors 'to Carter' Carburetor Corporation, St. Louis, Mo., a corporation of Delaware Application July 2, 1936, Serial No. 88,566

3 Claims.

This invention relates to carburetors `for internal combustion engines and consists particularly in novel inter-connection control means between the choke and throttle valves.

A copending application Serial No. 666,118,l

filed April 14, 1933, in the names of George M. Bicknell and'Otto Henning, and copending applications Serial No. 83,066, led June 2, 1936,

and Serial No. 89,088, led July 6, 1936, both in the name of August H. Blattner, illustrate carburetor choke and throttle valve interconnection mechanisms arranged to limit closing movements of the throttle valve to the fast-idle position when the choke'is closed and to force the choke valve substantially open when the throttle valve is open. The last two mentioned applications also illustrate means for locking the choke valve whenv both the choke and throttle valves are fully open.l

The present invention comprises a novel choke and throttle valve interconnection mechanism embodying fast idle, unloading, and choke lock features somewhat as in the above-mentioned applications, the mechanism being adapted to be applied to an automatic choke carburetorhaving the choke control mounted on the air horn and on the same side of the carburetor as the interconnection. The present construction embodies certain structural and functional diierences and advantages over the corresponding mechanisms of said applications.

One object ofthe present invention is to provide novel choke and throttle valve interconnection mechanism in which the principal parts thereof are compactly located near the lower portion ofthe carburetor.

Another object is to provide choke and throttle valve interconnection mechanism for a carburetor tachment to the intake manifold (not shown) of' an associated engine. Pivoted in the air horn on shaft 5 is anunbalanced butterfly typechoke valve 6, and throttle valve 1 is pivoted on shaft 8 in the lower portion of the-mixture passage. The

vfull closing. of the throttle valve.

(ci. zei-:52)

choke valve is provided with an automatic control mechanism, including a thermostat 30, in a housing 3| mounted adjacent the air horn. A. choke control of this type is more fully disclosed in Coiey patent No. 2,085,351. AdjacentA the 5 mixture passage is a vbowl 9 within liquid fuel is maintained at a substantially constant level by a float I0. Fuel from bowl 9 passes through metering jet II into main nozzle I2, discharging into the throat of the smaller venturi 3, and an 10 Vidling passage,.part of which is shown at I3.

Pivotally mounted on member I4 adjacent the throttle shaft 8 is. a cam-like member, generally indicated at I5, and having a laterally projecting pin I6 received in slot I1 in the lower portion l5 of link I8.- Link I8 is pivoted at its upper end to crank I9 rigid with the choke valve shaft 5. In the present instance, choke shaft 5 extends outwardly beyond the crank I9 for attachment of automatic choke control means (not shown) on 20 the'same side of the carburetor as the interconnection mechanism.

Throttle control crank 20 is -constructed as at 2| for manual operation and has an adjusting screw 22 for cooperation with cam-like member 25 I5, when the choke valve is closed, to prevent Projecting from crank 29 is a foot-like portion 23 having a toe 24 and a heel 25. Cam-like member I5 has a lateral pin 26 for cooperating with heel 25 to 30 manually'open the choke valve, and link I B has a lateral oiset 21 at its lower extremity for cooperating with toe 24 to lock the choke valve when both the throttle and choke are substanexaggerated for clearness. Preferably the throttle will be opened beyond the fast idle position for cold starting. During cranking, and after the engine starts to run, choke valve 6 may open to the extent indicated by the broken line f position (Figure 4) due to the slot and pin connection between cam-like member I5 and link A I8, without necessarilyvaifecting the position of the cam-like member. Also the throttle valve 50 may be fluctuated, in order to primethe engine by means of the accelerating pumpfwithout affecting the choke valve. As long as the choke valve remains -in a substantially closed position, high point l5a on the cam-like member will be 55 ypositioned to be engaged'by screw-22, to umu;v

. closer and closer to its fully closed position as the the closing movement of the throttle to the fast idle position. During opening 'of the choke valve,

the cam-like member rotates counterclockwise choke valve opens.

In case of overenrichment of the mixture during cranking, which may be due, for instance, to excessive fuel charges from the accelerating pump or to sticking of the choke valve, the intake sysl tem maybe unloaded by opening of the throttle valve, as shown in Figure 2, to the point where heel element 25 engages pin 26 to rotate camlike member I5 counterclockwise and open the choke valve. The ensuing gust of air through the carburetor and intake manifold serves to clean out excess fuel therein.

When the throttle valve has been fully opened, the choke valve is free to open farther, as shown in Figure 3, under the influence of the automatic choke control mechanism. When the choke has fully opened, lip 21 will lie beneath toe element 2l on the throttle crank so as to prevent closing movement of the choke valve as long as the throttle remains fully open. The lower portion of slot Ilis slightly enlarged to permit lip 21 to pass toe 24 and drop beneath the same by gravity. If desired this action may be made more certain by a spring.` The choke open lock featureis particularly useful in connection with though not limited in use to an automatc choke control as shown in copending application of I. E. Coney,

the choke is open, due, for instance, to accelera' tion or low speed operation'with the throttle open. the thermostat may cool sufllciently to partly vclose the choke, resulting-in excessive richness oi' the mixture. The choke open lockl permits restrictingthe heat applied to the thermostat when the choke is wideopen to prevent excessive heating of the thermostat and also stabilizes the choke valve under normal operating conditions.

After the choke valve has opened fully, the

throttle valve is free to move within its fullrange of operation without beingY ail'ected by the inter- 'mentsand positioning of the choke and throttle valves. The principal portions of the mechanism are located adjacent the lower part of the carburetor so as not to interfere with or beobstructed by the automatic choke control mechanism which, in the present instance, is mounted on the same side of the carburetor as the interconnectionv mechanism.

Obviously, the invention is not limited in details to thestructure shown, but may be modifled in various respects as would occur to those, skilled in the art, andthe exclusive use of all such modications as come within the scope of the appended claims ls contemplated.

We claim:

`1. In va carburetor, choke and throttle valves, a thermostatic control for said choke valve, members movable with said valves, a part pivoted adjacent the member movable with said -of said choke valve independently of said throttle valve.

2. In a carburetor, chokeand throttle valves having pivotal shafts, a thermostatic control for said choke valve, arms on said shafts, a cam-like member pivoted to the carburetor immediately adjacent said throttle shaft, and a link member connecting said cam-like member and said choke arm, one of saidmembers having a pintle thereon and the other having a slot receiving' said pintle whereby Vsaid link member is permitted substantial longitudinal lost motion relative to said-cam-like member, said .cam-like member having a plurality of portions at different distances from the pivotal center, thereof, and the arm on said throttle valve shaft having an abutment for selectively engaging said portionswhen said chokevalve is not fully open to variably prevent full closing of said -throttle valve, said throttle arm and said cam-like member having other abutments cooperating when said throttle is substantially opened, to take up the lost motion between said link member and said cam-like member andopen said chokel valve and alsocooperating when bothl of said valvesare substantially-fully open to lock saidchoke valve.v

3. In a carburetor, choke and throttle valves, a thermostatic control for said choke valve, members movable with said valves, a` part -pivotedzl adjacent the member movable with one of said valves, said last-'mentioned member having an abutment, and a link connecting said part and the member movable with the other of said valves,

and having a'projection disposed to underlie `said abutment only when both of said valves are` substantially fully open to prevent closing of.r :said choke valve independently of said throttle valve.

AUGUST H. BLATTNER. Panna. Komma. 

